The National Trust has said ash dieback is a "catastrophe for nature"- as it revealed it has suffered its worst year on record for the destructive fungus.

The charity has said it is set to fell over 40,000 ash trees at a cost of £2million because of the disease, the spread of which they say has been exacerbated by warmer weather and the impact of lockdown.

A warm and dry spring, paired with the national lockdown meaning teams of rangers were prevented from carrying out felling and maintenance work to ensure tree safety, has created a "perfect storm"allowing the fungus to ravage areas including Cumbria's Borrowdale region.

“Lockdown has meant we weren’t able to undertake regular conservation work and many of our rangers who have returned are now forced to spend time tree felling to manage safety,”said national tree and woodland advisor Luke Barley.

“Ash dieback is a catastrophe for nature. Our landscapes and woodlands are irrevocably changing before our eyes, and this year’s combination of a dry spring and late frost may have dramatically sped up the spread and severity of ash dieback.

“As well as the cultural impact of losing these historic sites, there are also implications for climate change as less carbon is sequestered, homes for wildlife are removed and people’s access to nature diminished."

Ash dieback is caused by a fungus called Hymenoscyphus fraxineus. Originating in Asia the fungus spread due to the movement of plants as part of the global trade.

The fungus spreads very quickly due to its windborne spores and weakens the tree, which poses a safety hazard.

“The issue of ash dieback is nothing new, but the speed at which is it spreading seems to have been exacerbated due to the weather, and the time and expense necessary to tackle it contributes to the perfect storm we are witnessing," said Mr Barley.

“There needs to be some recognition of this as a nationwide issue and an understanding of what is being lost.

"But also how we replace these lost landscapes.”

The National Trust has warned that between 75 – 95 per cent of all ash trees will be lost in the next 20-30 years –around 2.5 million trees on National Trust land alone.

The charity has appealed to the public to help in the fight to preserve the iconic tree by donating to their Everyone Needs Nature campaign, which aims to replace lost woodland.

It has also called for the issue to be written into the government’s recently published England Tree Strategy, which sets out national commitments around tree planting and woodland creation.